Repeatedly used containers, such as beer bottles, rub each other and are damaged in the respective stages, e.g., in the factory, during shipment, during recovery, and the like. Such damages can give an unfavorable impression to consumers. To prevent this, usually, after the containers are filled with a beverage such as beer and labeled, they are coated.
A prior art concerning a coating device is described in Japanese Patent Publication No. 1-59221. Japanese Patent Publication No. 1-59221 discloses a device provided with a coating belt which moves at a speed higher than the moving speed of a conveyor while being kept in contact with containers. While rotating the containers which move together with the conveyor, the device coats the entire surfaces of the containers by the coating belt. According to this device, to prevent that portion of the coating belt which is in contact with the containers from flexing, a tension pulley which can be positionally adjusted in a direction crossing the moving direction of the coating belt is provided at such a position that the coating belt is not in contact with the containers.
In recent years, a demand to use containers having various sizes has arisen. In the coating device described in Japanese Patent Publication No. 1-59221, the gap between the coating belt and a press contact plate or press contact belt which is arranged at a position to oppose the coating belt is fixed. Hence, in the coating device described in Japanese Patent Publication No. 1-59221, to change the size of the containers to be coated, the coating device must be remodeled according to the size of the containers.
In the usage where the size of the containers is changed frequently, frequent remodeling operation is required accordingly. This decreases the device operation hours and the number of containers that can be processed.
In general, after the container coating operation is ended, the coating belt must be cleaned. A coating liquid which drops from the coating belt during coating must be separated from a coating liquid which is washed off from the coating belt during cleaning or a cleaning liquid for cleaning. The coating liquid which drops from the coating belt during coating can be recovered and reused. The cleaning liquid which contains the coating liquid produced during cleaning must be discharged or reused after it is processed appropriately in consideration of the influence to the environment.
A mechanism for separate recovery or discharge must be designed in consideration of the maintenance easiness.
Japanese Patent Publication No. 1-59221 discloses nothing concerning the above respects.